A delivery firm has to deliver to three offices and to send 350 , 550 and 300 letters (letters are all the same content) to each office respectively. The delivery firm has three factories to operate from and the amount of letters available at each factory is 200, 750 and 400 respectively. The cost for delivery of one lot of letters from the factories to offices is below:

	office 1	office 2	office 3
Factory 1	24	20	16
Factory 2	18	14	8
Factory 3	28	24	22

(a) Formulate the problem as a linear programming problem so to minimize the daily delivery costs. (b) for initial table set up use each of the methods North West Corner, Least Cost and VAM. (c) Solve each of the above using MODI method. (d) Comment on the difference between the methods of setting up the initial tables and also of solving the problem, in the area of efficiency.